1. Field of the Invention
The present invention relates to a valve device for an internal combustion engine.
2. Description of Related Art
In a conventional valve device described in Japanese Patent Application Publication No. 2001-263015 (JP 2001-263015 A), for example, each cylinder is conventionally provided with an arm assembly constituted by a roller arm and two rocker arms formed separately, and positioning of the roller arm and the rocker arms of the each cylinder is adjusted by inserting respective shims having different thicknesses into a cylinder head and a carrier appropriately.
Conventionally, in an internal combustion engine provided with a valve device, it is widely known that a lift timing difference is caused between two intake valves so as to shift their valve-opening timings from each other and to generate a desired swirl flow, thereby improving combustion efficiency. Further, as a general valve device, a configuration, as described in JP 2001-263015 A, in which two rocker arms formed separately and two intake valves lifted along with pivoting of respective rocker arms is widely known. In a variable valve device described in JP 2001-263015 A, if the two rocker arms can pivot with a desired timing difference, it is possible to obtain a desired swirl flow as described above. Here, one of conceivable means for causing a plurality of rocker arms formed separately to pivot with a desired timing difference is that adjusters such as shims are inserted into the rocker arms so as to position the rocker arms, respectively, so that their pivoting timings are shifted from each other.